Lithium-Rich O2-Type Li0.66[Li0.22Ru0.78]O2Positive Electrode Material

Hirohito Umeno, Kosuke Kawai, Shin Ichi Nishimura, Daisuke Asakura, Masashi Okubo, Atsuo Yamada*


研究成果: Article査読

2 被引用数 (Scopus)


Increasing the energy density of lithium-ion batteries is an important step towards flexible electricity supply, which can be achieved by developing large-capacity positive electrodes. Lithium-rich oxides have been a longstanding research target because of their large capacity involving extra oxygen-redox reactions. In this work, we report the synthesis, electrochemical properties, electronic structure, and structural evolution of O2-type lithium-rich layered oxide Li1.22-xRu0.78O2. A robust Ru-O layered framework without Ru migration allows for unveiling the solid-state electrochemistry of O2-type lithium-rich layered oxides with possibility of a large yet stable extra capacity for oxygen-redox reaction. Using a combination of X-ray photoelectron spectroscopy, X-ray absorption/emission spectroscopy, and in situ/ex situ X-ray diffraction, we clarified that O2-Li1.22-xRu0.78O2 delivers a large capacity of 200 mAh g-1 in association with Ru5+/Ru4+ and Ru4+/Ru3+ two-electron redox reactions under a solid-solution process, but with no contribution from the extra oxygen-redox reaction.

ジャーナルJournal of the Electrochemical Society
出版ステータスPublished - 2022 4月 1

ASJC Scopus subject areas

  • 電子材料、光学材料、および磁性材料
  • 凝縮系物理学
  • 材料化学
  • 表面、皮膜および薄膜
  • 電気化学
  • 再生可能エネルギー、持続可能性、環境


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